How Many People Die From Lack of Health Insurance?

By Megan McArdle

It's a contentious question, but curiously, one that doesn't get debated nearly as fiercely as things like "how many uninsured people are there?" I find that surprising, because after all, we don't necessarily care whether people are marked by some survey as "insured" or "uninsured"; we care whether there is preventable suffering in the world.

But it turns out to be really hard to determine how many people die without insurance, which is the subject of this month's column. The most recent available study, which also had the largest sample and controlled for the most variables, found no effect at all--a result which surprised the hell out of its author, a former Clinton advisor. Other studies say the number is in the tens of thousands.

The left is predictably fond of the study which got the largest number, 45,000 a year. Unfortunately, its authors are political advocates for a single-payer system, who also helped author the notorious studies on medical bankruptcies. Those studies are very shoddily done, with parameters that somehow always conspire to produce the maximum possible number. In the first study, they set an absurdly low threshhold for what constituted a "medical bankruptcy". In the second, they chose 2006, the year after the 2005 bankruptcy reform act had driven an unprecedented spike in filings. It seems pretty likely that medical bankruptcies were bound to be overrepresented in 2006, since most financial events are easier to see coming than illnesses. But even if you disagree--and the authors offered an incredibly wan explanation of why they did--it's very clear that the people who filed in 2006 were not going to be a representative sample of bankruptcies in a normal year. I can't imagine why you would choose to study 2006 unless you were looking for biased results. I have to conclude that their political beliefs are affecting their work, which means I wouldn't touch that 45,000 number with a bargepole--I wouldn't cite anything they authored even if it offered to prove beyond a shadow of a doubt that I was right about everything.

The right, meanwhile, shuns the subject like the plague. It will not do anyone's career any good to be attached to an argument that sounds like the health care equivalent of "let them eat cake".

So allow me, maybe, to be the first. I'm afraid I'm not confident about any number. All of these studies suffer from unobserved variable bias, which is to say, the uninsured are not like the rest of us. (The long term uninsured, I mean; the short term uninsured are not a large problem for society). There are all sorts of reasons that people end up uninsured, but most of them are correlated with much poorer health outcomes, and only some of them end up recorded in our surveys.

To give you an example of what I mean, one of the two studies that went into the most commonly cited number--the roughly 20,000 a year figure from the Institute of Medicine and the Urban Institute--found that the highest mortality was not associated with being uninsured, but being on a government health care program. (the other excluded those patients). This was true even after they'd run all their controls. Given that the bulk of the coverage expansion in both the Senate and the House plans comes from Medicaid expansion, this is a little disturbing.

But how likely is it that Medicaid is killing people? Possible, I suppose, but not really all that likely. Medicaid and Medicare patients, too, are not like the broader population. The authors in fact recognized this fact in their paper, pointing out that these patients have higher rates of disability--but then failed to address the obvious question this raised about their data on the uninsured.

This problem plagues almost all of the studies on mortality and the uninsured. Probably the best one looked at patients who had been taken to the ER, which still showed higher mortality for the uninsured. But it's not clear that this indicates that lacking insurance is dangerous; it may be telling us that people who lack insurance have a lot of factors that lead to poorer health outcomes.

To my mind probably the single most solid piece of evidence is this: turning 65--i.e., going on Medicare--doesn't reduce your risk of dying. If lack of insurance leads to death, then that should show up as a discontinuity in the mortality rate around the age of 65. It doesn't. There are some caveats--if the effects are sufficiently long term, then it's hard to measure, because of course as elderly people age, their mortality rate starts rising dramatically. But still, there should be some kink in the curve, and in the best data we have, it just isn't there.

That doesn't mean I'm prepared to say that no one dies from lack of insurance. The data is messy, and the studies often contradict each other. Intuitively, I feel as if there should be some effect. But if the results are this messy, I would guess that the effect is not very big. At minimum, I think we should be pretty cautious about stating that we know how many people die from lack of insurance. We don't, and worse, we may never.